Adverse Prognostic Impact of Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Patients with Diffuse Large B Cell Lymphoma

Neutrophil-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been lightened as a prognostic factor in many types of solid tumor. However, there was a limited report for diffuse large B cell lymphoma (DLBCL). Thus, we investigated the impact of NLR and PLR on prognosis of patients with DLBCL. This study involved 234 DLBCL patients treated by rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP) at National Cancer Center, Korea. The median patient age was 57 years, and 135 patients (58%) were men. Clinical characteristics as international prognostic index (IPI) including age, performance, LDH, stage and extra-nodal involvement, were evaluated. NLR and PLR at diagnosis were calculated by CBC data from automated hematologic analyzer XE2100 (Sysmex, Kobe, Japan) or differential count which was done by manually using stained peripheral blood slide when CBC data showed flags in auto-analyzer. Hazard ratios (HRs) were determined in terms of risk for overall survival using Cox proportional hazard regression analysis. The mean percentage of neutrophils and lymphocytes was 60 (range, 5-95) and 12 (2-79), and the number of platelets was 257 × 10^9/L (28-839). The mean and standard deviation of NLR and PLR was 3.62 (±4.77) and 14.7 (±20.16), respectively. IPI and stage were predictors for prognosis (p <0.01), and both NLR and PLR showed significant association with poor prognosis of HRs of 1.14 [95% confidence interval (CI), 1.10 to 1.20] and 1.02 [95%CI, 1.02-1.03]. Although both NLR and PLR represented association with IPI, there were still prognostic impacts as HR of 1.12 and 1.02 with IPI in multivariate analysis. These findings suggest that NRL and PLR may be significant prognostic indicators for patients with DLBCL treated by R-CHOP.